CFile

CFile is a C++ class that is provided to simplify 825 file operations. CFile is a wrapper class around the standard C library FILE object. CFile also provides some useful features such as baud rate setting for the 825 serial ports.

Constructors

CFile(void);
CFile(const string& strFilename);
CFile(const char* pszfilename);

These constructors just create a CFile object without opening a file.

CFile(const string& strFilename, const string& strMode);
CFile(const string& strFilename, const char* pszMode);
CFile(const char* pszFilename, const string& strMode);
CFile(const char* pszFilename, const char* pszMode);

These constructors construct the file object and attempt to open the file.

Parameters

• strFilename - filename
• pszFilename - filename
• strMode - mode
• pszMode - mode

Examples

CFile fileLog("/mnt/fl1/log.txt", "a");
if(fileLog.IsOpen())
{
     fileLog.Print("Gross %s Tare %s Net %s\r\n", FormatGrossWt(1).c_str(), FormatTareWt(1).c_str(), FormatNetWt(1).c_str()); 
     fileLog.Close();
}

CFile fileLog("/mnt/fl1/log.txt");

This contructs the object to open later.

Member Functions

Open

Opens a specified file, or using the filename already stored in the object.

bool Open(const string& strFilename, const string& strMode);
bool Open(const string& strFilename, const char* pszMode);
bool Open(const char* pszFilename, const string& strMode);
bool Open(const char* pszFilename, const char* pszMode);
bool Open(const char* pszMode);

Parameters

• strFilename - filename
• pszFilename - filename
• strMode - mode
• pszMode - mode

Return Value

Returns true if successful or false if unsuccessful.

Remarks

Example

CFile file;
if(file.Open("/tmp/tmpfile", "w") == false)
{
    DisplayText(0, 0, "Error writing temporary file");
}

Close

Closes the file

void Close(void);

Parameters

Function does not accept any parameters

Retrun Value

Function does not return any result.

Remarks

For serial ports it may be necessary to provide some delay to allow all of the buffered data to be sent out of the port before closing the port.

Example

CFile file("/dev/ttyS1", "w");
file.Print("This is a test\r\n");
SleepSeconds(1);
file.Close();

SetSerial

Set the baud rate, number of data bits, parity, and number of stop bits for serial ports.

bool SetSerial(baud_index baud, data_bit_index = data8, parity_index = parityNone, stop_bit_index = stopOne);

Parameters

• baud_index
• data_bit_index
• parity_index
• stop_bit_index

Return Value

Returns true if successful, false if not successful.

Remarks

Examples

CFile file("/dev/ttyS1", "w");
if(file.IsOpen())
{
   file.SetSerial(CFile::baud9600, CFile::data7, CFile::parityEven, CFile::stopOne);
}

CFile file("/dev/ttyS1", "w");
if(file.IsOpen())
{
   file.SetSerial(CFile::baud19200);
}

ReadLine

Reads a text file a line at a time.

bool ReadLine(std::string& strLine);

Parameters

• strLine - string reference to return line read

Return Value

Returns true if line read, false if end of file

Remarks

Example

CFile file("/mnt/nand/apps/test/config.txt", "r");
if(file.IsOpen())
{
   string strLine;
   while(file.ReadLine(strLine) == true)
   {
       if(strLine.substr(0, 7) == "Setting")
       {
           // TODO Parse the settings line
       }
   }
   file.Close();
}

DeleteFile

Deletes a file

static bool DeleteFile(const string& strFilename);
static bool DeleteFile(const char* pszFilename);

bool DeleteFile(void);

Parameters

• strFilename - string filename to delete
• pszFilename - pointer to null terminated character array filename to delete

Return value

Returns true if successful, false if not successful.

Remarks

Versions of this fuctions that accept a filename are static so they do not require an CFile object.

Examples

string str = "/tmp/tmpfile";
CFile::DeleteFile(str);

if(CFile::DeleteFile("/tmp/tmpfile") == false)
{
   DisplayText(0, 0, "Delete file error");
}

CFile file("/tmp/tmpfile", "w");
if(file.IsOpen())
{
   file.Print("This will not exist very long\r\n");
   SleepSeconds(1);
   file.Close();
   SleepSeconds(1);
   file.DeleteFile();
}

IsReady

Check the state of the serial CTS input

bool IsReady(void);

Parameters

Function does not accept any parameters.

Return Value

Function returns true if CTS is active, false if CTS is inactive.

Remarks

IsReady() will return false if the CTS line is unconnected. Printers or other devices must be wired correctly for applications to be able to use this function to determine their readiness. The main board COM3 is not currently supported by this function.

Example

CFile fileLogOutput("/dev/ttyS1", "w");
if(fileLogOutput.IsOpen())
{
   fileLogOutput.SetRTS(true);
   if(fileLogOutput.IsReady() == false)
   {
      DisplayText(0, 0, "Printer offline, or disconnected");
   }
}

SetRTS

Set the state of the serial RTS output

bool SetRTS(bool bRTSOn = true);

Parameters

• bRTSOn - true to turn on RTS output, false to turn off RTS output

Return Value

Returns true if successfully set RTS state, false otherwise.

Remarks

Example

CFile fileLogOutput("/dev/ttyS1", "w");
fileLogOutput.SetRTS(true);

GetFile

FILE* GetFile(void);

Print

Outputs text which may include format specifiers. For each format specifier an additional parameter must be provided.

void Print(const string& strFormat, ...);
void Print(const char* pszFormat, ...);
void Print(const string& strFormat, va_list& args);
void Print(const char* pszFormat, va_list& args);

Parameters

• strFormat - string to output, may include format specifiers such as C printf statements
• pszFormat - pointer to null-terminated string to output, may include format specifiers
• ... - variable list of arguments that should match up with format specifiers
• args - variable list of aguments structure

Return Value

Function does not return a value.

Remarks

Examples

string str = "Hello World\r\n";
file.Print(str);

int n = 5;
string str = "ABC";
file.Print("Number: %d String %s\r\n", n, str.c_str());

// This is a function to log update data to two devices
// g_fileLog1, and g_fileLog2 are globals that should already have been opened before this function is called.
void LogOutput(const char* fmt, ...)
{
   va_list args;
   va_start(args, fmt);

   g_fileLog1.Print(fmt, args);
   g_fileLog2.Print(fmt, args);

   va_end(args);
}

SetNonBlocking

void SetNonBlocking(void);

Read

bool Read(void * ptr, size_t size);

Write

bool Write(void * buf, size_t size);

GetBytesRead

size_t GetBytesRead(void);

GetbytesWritten

size_t GetBytesWritten(void);

Seek

bool Seek(long int offset, long int origin = SEEK_SET);